What is the purpose of a superheater in a boiler system?

• A. To condense steam back to water.
• B. To preheat feedwater.
• C. To reduce boiler pressure.
• D. To raise steam temperature above saturation, increasing thermal efficiency and turbine output.

Answer: (D)

A superheater heats the steam beyond its saturation point, creating superheated steam. By adding heat after the boiler, the steam’s temperature rises above the saturation temperature for that pressure, which increases the average temperature at which heat is added in the cycle and reduces moisture in the steam. This leads to more work from the turbine for the same boiler conditions and improves efficiency, plus less blade erosion from wet steam. It isn’t about condensing steam, which happens in a condenser; it isn’t about preheating feedwater (that’s done by economizers or feedwater heaters); and it doesn’t reduce boiler pressure—the superheater’s role is temperature, not pressure.